Automotive cooling system flushing method



April 27, 1965 FALK 3,180,759

AUTOMOTIVE COOLING SYSTEM FLUSHING METHOD Filed May 21. 1964 4&5 50

p33 INVENTOR. b HENRY J. FALK United States hatent 3,180,759 AUTGMOTWE CGQLING SYSTEM FLUSEHNG NLEETHQD Henry J. Falls, Kenmore, N.Y., assignor to Union Carbide Corporation, a corporation of New York Filed May 21, 1964, Ser. No. 3d9,173 2 Gaims. (Cl. 134-22) The present application is a continuation-in-part of application Serial Number 136,336, filed September 6, 1961, now abandoned.

The invention relates to a novel method for flushing the cooling systems of automobiles.

The cooling system of conventional automobiles comprises a radiator, an engine having flow paths therein, a Water pump, and several hoses and conduits connecting these parts. The water pump, which can be considered as a part of the engine, is usually attached to the lower front of the engine and communicates with the flow paths therein. In general, a lower radiator hose connects the water pump and the bottom of the radiator, and an upper radiator hose connects the upper end of the engine flow paths and the top of the radiator, thereby effecting a complete flow circuit through the engine and the radiator. A thermostat is usually placed in the top of the engine near the upper radiator hose to block Water circulation when the engine is operating below desired temperatures.

A heater is also included in the cooling system of most automobiles, and is generally located near or in the interior of the automobile. The heater is connected to the other parts of the cooling system by a heatersupply hose slipped tightly over a nipple fitted in a heatersupply aperture on the top of the engine and over a nipple on the heater, and by a heater-return conduit connected to the heater and emptying into the water pump through an, aperture therein.

it is well known that automotive cooling systems must be flushed periodically to remove rust, acidic materials, and various other contaminants originating during engine operation. If such a system is not properly flushed, the contaminants may cause corrosion of the metallic parts present, foaming of the coolant, and clogging of the flow paths. Moreover, when such a system is flushed, it is desirable to remove all of the old, contaminated coolant before filling the system with fresh coolant, since any remaining contaminated coolant obviously adversely affects the fresh material. Unfortunately the removal of all of the old coolant can be quite ditiicult.

In a fully assembled automobile in operating condition, there are generally three openings which are provided for communication with the cooling system. One of these is a radiator filling hole on top of the radiator; another is a radiator drain cock on the bottom of the radiator; and the other is a drain plug, or in older cars a drain men, on the bottom of the engine. Obviously,

these three relatively small openings cannot permit rapid introduction and removal of flushing water, which is required for effective flushing. Moreover, the drain plug on the bottom of the engine can be reached only from underneath the car in most instances, and is generally inaccessible.

The most effective flushing procedure known to date involves disconnecting the upper radiator house, which connects the radiator and the engine, from the radiator followed by the introduction of fresh water into the engine through this hose. The fresh water and old coolant will be forced out of the system chiefly through the radiator filling hole. This procedure provides good cleaning if the thermostat in the engine near the top radiator hose is first removed. Otherwise, the thermostat will close upon contact with the relatively cool fresh water, and water circulation will be substantially blocked. This is unfortunate since removal of the thermostat is usually difiicult and time-consuming. As a result, in actual practice ineffective short-cuts have been taken which fail to remove all of the hold, harmful coolant and other harmful materials.

It is an object of the invention, therefore, to provide a novel, convenient, and effective method of flushing an automotive coolant system, which does not require the removal of the thermostat or the engine drain plug.

Broadly stated, the invention achieves the above objects by a method which comprises disconnecting the heater supply hose from the heater supply aperture on the top of the engine, introducing flushing fiuid into the cooling system through the heater-supply aperture on top of the engine from whence it flows through the cooling system and exits therefrom through the radiator filling hole and the heater supply hose. More specifically, the method of the invention comprises introducing tap water into the cooling system through the heater-supply aperture and intermittently injecting air along with the tap water.

In the drawing:

FIG. 1 is a schematic View of a conventional automotive cooling system and the liquid flow therethrough in accordance with the invention; and

FIG. 2 is a sectional view of a suitable apparatus for carrying out the method of the invention.

Referring now to the drawing, and particularly FIG. 1, the conventional automotive cooling system schematically shown there comprises an engine 2 having flow paths therein for a coolant, a radiator 4, a heater e, and a water pump 8 attached to the engine 2. The radiator 4 is connected to the water pump 8 by a lower radiator hose iii, and to the engine 2 by an upper radiator hose 12. A heater-supply aperture 13 is provided at the top of the engine 2, and a heater-supply hose 14, which in normal operation fits on the heater-supply nipple 16 provided in the aperture 13 and on the heater nipple 18 on the heater 6,'is shown disconnected from the heatersupply nipple 16. A heater-return conduit 21) provides a flow connection between the heater 6 and the water pump 3.

A drain cock 22 is provided at the bottom of the radiator 4-, and a drain plug 24 is provided near the bottom of the engine 2. The radiator 4 has a radiator filling hole 26 at the top which is usually covered by aradiator cap (not shown). A heater valve 28 regulates the liquid flow through the heater 6, and is usually controlled from the instrument board in the interior of the automobile. In some cars, however, the valve 28 requires for its operation a Vacuum supplied by the engine 2. A thermostat 29 fits in the engine 2 near the upper radiator hose 12, and regulates circulation between the engine 2 and the radiator 4.

Also shown in the schematic view is a fluid-deflecting assembly 36. This is not a part of the cooling system, but such an assembly deflects away from the engine 2; any liquid emerging from the radiator filling hole 26 during flushing. The construction of the deflecting assembly 3%) is obviously not critical, but a preferred embodiment consists of a standard radiator cap 32 having a holein its top and a U-shaped nipple 34- attached over the hole, and a hose 36 fitted on the nipple 34.

Shown fitted over the heater-supply nipple 16 is a' connecting hose 33, the other end of which fits on the flushing apparatus 49, illustrated in cross-section in'FIG. 2. As there shown, the apparatus iii, which can be made of any suitable material such as brass, aluminum, and plastic, comprises a liquid conduit 42 and an air pipe 44 opening into a side of the conduit 42. One end of the conduit 42 alias other end of the conduit 42, there is a tubular piece 43 preferably having two different outside diameters 50 and 52,- the smaller-diameter being nearen theend. The tubular piece 48 is adapted to fit inside the connecting hose 38 mentioned above which fits the heater-supply nipple .16

. on the engine 2, as shown inthe schematic view. Diameters t) and 52 are preferably ,4; inch and A'inch respectively since' these twosizes correspond to the size of the ting58 attached to the connection 56. Also in the pipe 44 is an orifice .60 which limits airflow into-the conduit 42. The orifice 6t can be located at any place in the pipe 44, including the fitting 58, as an integral part thereof, but preferably the orifice 560 is provided in the form of a flat plate. 62. having the orifice therein and which is held in placebetween the connection 56 and the fitting 53. Separate plate eZperrnits easy cleaning of the orifice 6i and also permits one tochange the size of the orifice (it? without completely rebuilding the apparatus. Preferably, the orifice is between about 0.06 and about 0.10 inch in diameter, as will be discussed below.

Referring still to the drawing, an automotive cooling system is flushed in accordance, with the invention by removing the radiator cap (not shown) which covers the radiator filling hole '26,.placing .the. deflecting assembly .30 over the hole 26, disconnecting the heater 6 from the heater-supply nipple .16, and: introducing a flushing fluid into the cooling system'through the heater-supply nipple 16. V The flow of the fluid through the cooling system. is indicated by the arrows in the drawing. .As there shown,

. the fluid enters the engine 2 from the heater-supply nipple 16, and most of it flows down through theengine 2, out to the water pump 8, through the hose 1%, up through the radiator 4-, and out the filling hole 26 into the fluid-defleeting assembly 3% Some of the fluid from the heatersupply nipple 16 will flow up through the thermostat 29 and through the upper radiator hose lzbefore the .relatively low temperature of the fluid closes the. thermostat 29. Even after the thermostat 29closes, however, enough fluid will still flow through the thermostat. 29 to clean the relatively small radiator. hose '12 effectively, since'thermostats are generally provided with small vent holes.

With a heater in the cooling'system, as shown in the drawing, part of theflushing fluid will simultaneously flow from the water pump '8, through the heater-return conduit 29, through the heater 6, and out the heater-sup ply hose 14. The heater valve 28 must be at least partial- .ly open and should befully open. to permit rapid flow.

Therefore, the heater controls on the instrument board of the automobile are set on high' for best results. If the valve 28 is operated by a vacuum, the engine 2is idled to supply the vacuum. Itwill be noticed that all parts of the coolingsystenrare. flushed by a flow reverse to normal, which is most effective forcieaning the system.

An important feature of the. present invention is that the heater is flushed while at the same time. the possibility of damage to the heater, if the heater valve 28 is not fully opened, or if the heater is clogged or closed, is avoided.

Damage to the heater is avoided by virtue of the. manner. in which flushing fluid. is introduced into the cooling system in the present invention. For example, if the flushingfluid, at pressures of up to 80 psi, Where introduced at the heater supply hose 14, instead of at 16, the heater would burst or at least be severely damaged it the ,heaterwas clogged. Also, if-flush water is introduced intoheatenreturn hoseZti, afterdisconnecting hose 26 from pump 8, damage to. the heater will result if valve 23 is not fully open, or if the heater is clogged. On the other hand, in the present invention, where the flushing fluid is ---has a connection 46 adapted to fit on a flushing liquid- I ....supply hose,suitably awstandardgarden hose. -Aththe introduced at 16, the pressure at the heater is always be low a value which could cause damage, even if .theheater were clogged or the heater valve inadvertently left in a closed position.

Using the arrangement of the present invention, even if the heater valve is inadvertently left in the closed position, damaging pressures cannot be developediat the heater since the open radiator filling-holeacts to relieve the PIESSUIB.

Since water is convenient and inexpensive, it is generally used as the flushing fluid forcleaning cooling systems. Normal city water pressure is betweenZO and pounds per square inch, and will deliver about 5 to 25 gallons of water per minute to the cooling system dependingon the size and length of thewaterhose andpthe.Waterpressure.

A water flow in excess of 10 gallons ,perrninuteisdesirable for mosteffective cleaning. .Moreover, intermittent air injections into the flushing, water improved the cleaning action ofthe method .of the invention. It has been found that air flow rates between 1. and 15 standard cubic feet per .minute are preferablefor both cleaniugthe'cooling system and; avoiding excessive air .pressureswhich may burst: the. hoses and harm .the cooling system in, general.

An orifice having a 0.06 to 0.10 inch diameter. will permit air fiow IBIGSIOf between 1 and 15 standard cubic feet per-minute at the air. pressures usually available in most servicestations, i.e., up to p.s.i. In theapparatus'4i), the. orifice'oti is expressly. provided for. avoiding too high pressures in the cooling system.

The apparatus '49 of the inventiomwhen attached to the heater-supply nipple; 16 by the hose 138, to a water hose at connection 46, and to an. air hoseat fitting 53,

permits convenient and safe air injections along with. the flushing. water. 'The valve 54 controls the frequency of .the air injections, and the. orificefitilimits air flow to an acceptable rate.

The. above apparatus was usedi in accordance withthe method of the invention to clean: a cooling system containing 47%..glycol, and within 5 minutes no glycol remained inthe system. Moreovenonly about a minute was required to ready-the cooling-system for flushing by course, the-drain cock 22 on the-bottomof" the radiator may be opened, either before -or afterfiushing, to'drain the radiatonbut the removal of agreater volume of liquid may be required for the addition of larger volumes of antifreeze' Removal of the drain plug 24- will drain this extra-volume; but as stated before-this'is generally quite diflicult. The mostconvenientprocedure isto inject air into the system while the drain-cock 22 is open. About 65 percent of'the capacity 'ofthe system can be emptied by this procedure. This permits a normal, addition-of antifreeze to the system without removal of the drain-plug 24, and moreoverthe p'rocedureis quite simple, es ecially when the apparatus is being used."

The method of the invention obviates, the removal of the thermostat and engine drain, plug, and therefore minimizes the time and effort required for flushing automotive coolingsystems. Moreover, the method disclosed herein provides aclean,uncontaminated.cooling system i even though'thelabor involved is reduced.

What is claimed is:

1. A method fonflushiug an automotive cooling system comprising a radiator having anorm'ally closed'filling hole near its top, anengine havingflow paths connected with said radiator' through an upper radiator hose having a normally closed thermostatic valve andthrough a lower radiator hose, saidengine also having a heater supply aperture near the top portion thereof incommunh catronvwith saidfiow. paths, a heater connected. to said heater supply aperture through a heater inlet hose, a water pump communicating with said radiator and a heater return hose connected between said heater and said water pump; said method comprising:

(1) opening said radiator filling hole,

(2) disconnecting said heater from said heater supply aperture, and

(3) introducing water under pressure into said cooling system through said heater supply aperture to cause said Water to circulate through said engine cooling system and exit by passing through said radiator and out said radiator filling hole, and also by passing through said heater and said heater inlet hose.

2. A method for flushing an automative cooling system comprising a radiator having a normally closed illing hole near its top, an engine having flow paths connected with said radiator through an upper radiator hose having a normally closed thermostatic valve and through a lower radiator hose, said engine also having a heater supply aperture near the top portion thereof in com munication with said flow paths, a heater connected to said heater supply aperture through a heater inlet hose, a water pump communicating with said radiator and a g heater return hose connected between said heater and said water pump; said method comprising:

(1) opening said radiator filling hole, (2) disconnecting said heater from said heater supply aperture, and (3) introducing water under pressure and pressurized air into said cooling system through said heater supply aperture to cause said water and pressurized air to circulate through said engine cooling system and exit by passing through said radiator and out said radiator filling hole, and also by passing through said heater and said heater inlet hose.

References Qited by the Applicant UNITED STATES PATENTS 1,887,985 11/32 Auker. 2,387,324 10/45 Glickman. 2,482,904 9/49 Dougherty et al. 2,488,089 11/49 Mayo.

2,505,303 4/50 Randa. 2,835,234 5/58 Rasch.

DONALL H. SYLVESTER, Primary Examiner. 

1. A METHOD FOR FLUSHING AN AUTOMOTIVE COLLING SYSTEM COMPRISING A RADIATOR HAVING A NORMALLY CLOSED FILLING HOLE NEAR ITS TOP, AN ENGINE HAVING A FLOW PATHS CONNECTED WITH SAID RADIATOR THROUGH AN UPPER RADIATOR HOSE HAVING A NORMALLY CLOSED THERMOSTATIC VALVE AND THROUGH A LOWER RADIATOR HOSE, SAID ENGINE ALSO HAVING A HEATER SUPPLY APERTURE NEAR THE TOP PORTION THEREOF IN COMMUNICATION WITH SAID FLOW PATHS, A HEATER CONNECTED TO SAID HEATER SUPPLY APERTURE THROUGH A HEATER INLET HOSE, A WATER PUMP COMMUNICATING WITH SAID RADIATOR AND A HEATER RETURN HOSE CONNECTED BETWEEN SAID HEATER AND SAID WATER PUMP; SAID METHOD COMPRISING: (1) OPENING SAID RADIATOR FILLING HOLE, (2) DISCONNECTING SAID HEATER FROM SAID HEATER SUPPLY APERTURE, AND (3) INTRODUCING WATER UNDER PRESSURE INTO SAID COLLING SYSTEM THROUGH SAID HEATER SUPPLY APERTURE TO CAUSE SAID WATER TO CIRCULATE THROUGH SAID ENGINE COOLING SYSTEM SNA EXIT BY PASSING THROUGH SAID RADIATOR AND OUT SAID RADIATOR FILLING HOLE, AND ALSO BY PASSING THROUGH SAID HEATER AND SAID HEATER INLET HOSE. 